Title: Historical Bolide Infrasound Dataset (1960�1972)

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1. Dataset Overview
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This repository contains scanned strip-chart records, digitized waveforms, and summary tables for 
ten confirmed bolide events recorded by the U.S. Air Force Technical Applications Center (AFTAC) 
infrasonic network between 1960 and 1972. Each event folder houses the original images (in multiple 
states of processing), the final waveforms in numerical form, and relevant illustrative figures. 
The top-level directory provides summary tables (.xlsx and .txt) containing overall event metadata.

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2. Repository Structure
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.
+-- tables/
�   +-- AFTAC_Stations_table.xlsx
�   +-- AFTAC_Stations_table.scv
�   +-- AFTAC_Stations_table.txt
�   +-- event_parameters.txt
�   +-- response_function.txt
�   +-- signal_amplitude_period_measurements.xlsx
�   +-- ...
+-- bolide-A_YYYY-MM-DD/
�   +-- *.png            # Overlay plots or station-based figures
�   +-- images/
�   �   +-- raw/             # Original scanned charts (HF (*hf.tiff) and LF (*lf.tiff) if available)
�   �   +-- cleaned/         # Images with extraneous marks removed
�   �   +-- straight/        # Geometrically corrected images
�   +-- waveforms/
�       +-- original/        # Digitized waveforms without instrument response
�       +-- with_response_function/
�       +-- YYYY-MM-DD_original.csv  		# Consolidated waveforms for all stations/channels (without instrument response)
�		+-- YYYY-MM-DD_with_response.csv  	# Consolidated waveforms for all stations/channels (with instrument response)
+-- bolide-B_YYYY-MM-DD/
�   +-- (same structure as above)
+-- [Additional event folders for a total of 10 events]
+-- README.md


Notes on Key Folders

tables/
	Contains top-level summary sheets (in .xlsx and .txt) describing each event (date, approximate location, known yields, station coverage, etc.).
	These master files enable a quick overview and cross-event comparison.

event-X_YYYY-MM-DD/
	Each of the ten events is identified by the date (YYYY-MM-DD) preceded by a short descriptor (e.g., bolide-01_1960-11-02).
	This folder holds .png images of plotted waveforms, overlays of corrected vs. uncorrected data, or multi-station charts.
		images/: Stores the scanned strip charts in three states:
			raw/: Unaltered, high-resolution scans of both high-frequency (HF) and low-frequency (LF) passbands, if available.
			cleaned/: Images where non-waveform markings (stamps, pen scribbles) have been removed.
			straight/: Images that also received geometric corrections to address curved pen traces.
		waveforms/: Contains the digitized data:
			original/: Time�amplitude files (ASCII) without instrument-response correction.
			with_response_function/: Time�amplitude files after applying the general response function.
			YYYY-MM-DD.xlsx: A consolidated spreadsheet collecting station�channel waveforms and metadata for this event.


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3. Data Contents and Formats
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Scanned Charts (images/)
	Typically in TIFF (300�600�dpi).
	Subfolders separate unaltered scans (raw) from cleaned images and those corrected for geometric distortions (straight).
	Low-frequency (LF) passband charts are included alongside high-frequency (HF) scans for completeness, although only HF waveforms have been fully digitized.

Waveforms (waveforms/)
	original/: Contains time�amplitude pairs in ASCII .txt files, preserving the sampling interval and amplitude scale but not applying instrument corrections.
	with_response_function/: Contains parallel ASCII .txt files with the general AFTAC response function (Flores�et�al., 1975) applied.
	YYYY-MM-DD.xlsx: Combines these waveforms into a single spreadsheet for that event, allowing multi-channel or multi-station comparison in one file.

Summary Tables (tables/)
	Provide an overview of all ten events, referencing key parameters like peak-to-peak amplitudes, periods at maximum amplitude, station coverage, or approximate event yield.
	.txt versions offer a plain-text alternative for those not using spreadsheet software.

Figures
	.png images showing example plots (e.g., overlay of original vs. corrected waveforms).
	Each event�s subfolder includes station-level or combined channel-level figures for quick visualization.


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4. Usage Guidelines
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Image files:
	Open in any standard image viewer.
	raw/ vs cleaned/ vs straight/ reflect successive processing stages.
	Low-frequency scans are available but not digitized, allowing future expansions if needed.

Waveform text files:
	Typical file naming might be stationID_ch#.txt, containing columns labeled Time [s] and Amplitude [Pa].
	The with_response_function subfolder repeats these with the AFTAC response function applied.

Combined spreadsheet (.xlsx):
	Summaries each recognized station�channel pair with columns for time and amplitude, plus any relevant notes about filtering or gain.
	Convenient for multi-channel or multi-station comparison within a single file.

tables/ folder:
	Master event_metadata files describing event date, approximate location, known yield, station coverage, etc.


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5. Known Limitations
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Station metadata gaps: Exact station coordinates, microphone replacement records, or wind-pipe filter details are not preserved.
Timing reference: All waveforms have time starting at 0�s for each chart, not indicating absolute UTC.
Geometric distortions: Charts predating 1971 can exhibit pen-drum curvature, partially corrected in �straight� images. Some residual distortion may remain.
Low-frequency passband scans are provided but are not digitized; only the high-frequency band underwent full digitization and amplitude calibration.

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6. Citation and References
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When using this dataset, please cite both the data paper and the original references documenting its creation:

Data Paper: 

Silber et al. (2009): An estimate of the terrestrial influx of large meteoroids from infrasonic measurements. J. Geophys. Res.: Planets, 114(E8).
ReVelle (1997): Historical Detection of Atmospheric Impacts by Large Bolides Using Acoustic-Gravity Waves. Ann. NY Acad. Sci., 822, 284�302.